During some medical procedures, specifically endoscopic procedures, it is necessary to insert medical instruments, such as an endoscope, into the mouth and down the trachea or esophagus of a patient. It is common to use in such procedures a bite block or mouthguard to protect both the patient's mouth from the endoscope and the endoscope from the patient's mouth. The bite block or mouthguard essentially maintains the patient's mouth in the open position, providing an opening through which the endoscope can be passed, and prevents the patient from biting down on the endoscopic instruments, which are often quite expensive. Bite blocks capable of such function are generally known in the art; bite blocks designed for use with sedation and analgesia delivery and patient monitoring systems, however, are not.
In order to increase comfort and reduce patient resistance to the advancing of the scope, patients are often sedated during endoscopic procedures. In the case when the particular sedation drugs are respiratory depressants, there exist certain well-known risks related to patient respiration, including hypoventilation, oxygen desaturation, and apnea. In order to mitigate these risks, supplementary oxygen and respiratory monitoring are often utilized. Both the administration of supplementary oxygen and the sampling of respiratory gasses for monitoring require access to the patient's respiratory orifices, usually accomplished via oral-nasal cannula. Difficulties sometimes arise, however, when simultaneously managing the scope, delivering supplementary oxygen, and sampling respiratory gasses via the oral cavity. If the oral cavity could be reserved for exclusive use by the endoscope and the nasal passages used for oxygen delivery and respiratory sampling, the difficulty would be greatly reduced. Unfortunately, this method would require that the patient inhale and exhale only through the nasal passages for the duration of the procedure; in a real-world scenario, however, this is not the case.
It is therefore desirable for endoscopic procedures that require sedation to allow maneuvering of an endoscope into the oral cavity simultaneous with oral and nasal oxygen delivery and expired gas sampling. It indeed requires little imagination to see that accommodating all three activities simultaneously through the oral cavity with instruments not designed to be used together would prove troublesome. It follows that, as the endoscopy is the main focus of the procedure, it would take priority in use of the oral cavity over the other two functions. While focusing on the endoscope, an oral-nasal cannula is rather easily bumped and relocated during the maneuvering of the scope, leaving its oral ports situated too far from the oral cavity and occasionally causing bruising internal to the nasal passages. The consequence is decreased effectiveness in the administration of supplementary oxygen and sampling of respiratory gasses, which in turn may compromise patient safety.
In addition, in current practice, some doctors use a finger to help guide the endoscope into the mouth and down the trachea or esophagus of the patient. To do so, a doctor may stick a finger inside a patient's mouth, outside of the bite block, in order to control the endoscope near the opening to the trachea or esophagus. This requires that the finger be inserted at least to the depth of the end of the bite block, which may cause the bite block to move around. This adds to the risk that, during all of the jostling of the bite block associated with the maneuvering of the endoscope and insertion of a finger, the oral ports of the cannula may be unintentionally relocated away from the oral cavity.
It is therefore the object of the present invention to provide a bite block with means for locating and protecting the oral ports of an oral-nasal cannula and to facilitate simultaneous use of the oral cavity for an endoscopic diagnostic or surgical procedure, supplemental oxygen delivery, and respiratory sampling.